The present invention relates to a method for preparing a microarray comprising a hydrogel layer topographically structured with microwells for screening and cell culture experiments as well as said microarray itself. The invention can be employed in high throughput cell screening for pharmaceutical and diagnostic applications, basic biological studies, genetic assays, in systematic cellular knock-down, regenerative medicine and in tissue engineering. Specifically, the invention is useful for studying in vitro mammalian somatic stem cells and elucidating the role the microenvironment (niche) of these cell plays in stem cell fate, i.e. in differentiation, self-renewal and proliferation.
Microarrays for biomolecular and/or cellular probes as such are well known and widespread.
US 2006/0160066 A1 relates to a microarray platform for the culture of cells comprising a plurality of microspot islands on or microwells in a hydrogel substrate, wherein said microspot islands or microwells comprise an insoluble factor or an insoluble and soluble factor, wherein the insoluble factor promotes cellular adhesion.
US 2003/0044389 A1 describes a method of profiling cells with respect to their ability to respond to external biochemical stimuli in the microenvironment, which involves arraying cells on a planar surface through binding to immobilized probes such as signaling cues and specific binding partners for cell surface molecules.
U.S. Pat. No. 7,595,157 B2 discloses a microarray for assaying a target material in a biological sample comprising a solid, flat substrate functionalized with organic molecules, a polymerized hydrogel layer including anchoring moieties and a plurality of different probes linked to the anchoring moieties in the polymerized hydrogel layer to create microspots.
U.S. Pat. No. 7,588,906 B2 relates to a method of attachment of biomolecules such as peptides and proteins by immobilization on modified surfaces through a polyacrylamide-based polymerization reaction.
U.S. Pat. No. 6,372,813 B1 relates to a method for preparing a crosslinked polyacrylamide hydrogel array comprising one or more attached biomolecules, whereby attachment occurs via 2+2 photocycloaddition between one or more reactive sites of the biomolecule and on the polyacrylamide reactive prepolymer.
U.S. Pat. No. 6,174,683 B1 describes a method for preparing a biochip comprising a solid substrate to which is bound covalently a polyurethane-based hydrogel derivatized with covalently bound biomolecules.
Thus, from the prior art the use of hydrogels for microarrays, to which biomolecules are attached, is known. These arrays exist in the form of microspots on planar surfaces as well as microwells etched into the hydrogel and can be used for studying the biochemical microenvironment of adherent cells.
There is, however, no microarray which allows for analysis of both biochemical and biophysical niche effectors separately or simultaneously for adherent as well as non-adherent cells. Further, due to the spotting techniques used to distribute biomolecules in microwells of known microrrays, there is little spotting precision and limited possibility of modulating biochemical parameters.